Blood types - also known as the ABO system, blood types correspond with specific blood cell characteristics based on the presence or absence of certain antigens on the red blood cell surface; the 4 blood types are A, B, AB, and O.

Chain of custody DNA test - a legal term for a test that is performed to ensure the integrity of the results; typically, the results of a chain of custody test are court admissible; these tests cost more than in-home tests because of the collection and administrative procedures necessary to ensure the chain of custody is strictly followed

Child Support Enforcement Program (CSE) - a national program established in 1975 to ensure that both parents are financially responsible for a child; this program is enforced through the coordination of federal, state, local, and tribal child support agencies

Combined Paternity Index (CPI) - a common statistical result from paternity tests, representing the overall odds that a random, untested male could have the same genetic profile as the alleged father being tested; for example, if a paternity test resulted in a CPI of 300,000, this would mean that the odds that another male (not the alleged father) is the biological father of the child would be 1 in 300,000 - the probability of paternity for the alleged father in this case, then, would be 99.99967%; similar values are given for maternity, siblingship, grandparentage, and genetic reconstruction tests

Disestablishment of paternity - the legal determination that a man is not the father of a child; some states have provisions for disestablishing paternity, although many courts are reluctant to break ties between fathers and children because of the emotional impact it may have on the children

Identifiable information (adoption) - descriptive details in an adoption case that may lead to the positive identification of an adopted person, birth parent, or other birth relative; mutual consent between the adopted person and the birth family is typically required to access this information; this information frequently includes the current name and contact information of a person involved in an adoption case

Non-identifiable information (adoption) - descriptive details about adopted persons and their birth relatives that are generally released to adopted persons over the age of 18 in the United States; some states charge fees for the release of this information; this information often includes:

Date and place of the adopted person's birth.

Age and physical description of the birth parents.

Race, ethnicity, religion, and medical history of the birth parents.

Birth parents' educational and occupational status at the time of the adoption.

Power of exclusion - the power of a test to eliminate a certain percentage of the population from being biologically related to an individual; for example, if a paternity test using blood typing has a power of exclusion of 30%, only 30% of the male population could be eliminated from being the biological father of a tested child

Prenatal testing - DNA testing that is performed before a child is born; because DNA is present at the moment of conception, testing can be performed to verify biological relationships before birth; the DNA analysis is identical to testing performed after the child is born except that the child's DNA is collected through amniocentesis or chorionic villi sampling; DNA can also be collected from the umbilical cord upon the birth of the child

Probability of paternity - a statistical value for the odds that an alleged father is the biological father of a child; this value is derived from converting the Combined Paternity Index (CPI) into a percentage; probabilities of maternity, siblingship, grandparentage, twin zygosity, and relatedness are all calculated in the same way

Restriction fragment length polymorphism (RFLP) - a process by which DNA samples are cut into specific fragments of varying lengths for analysis; a child's fragments will be the same length as the fragments of his or her biological parents; similarities in fragment lengths can be used to verify other biological relationships

Rh factors - inherited antigens often found on the blood cells; some individuals have these antigens (Rh+) while others do not (Rh-); the presence of Rh factors, in conjunction with blood typing, has been used in the past to determine paternity

X-ray diffraction analysis - a laboratory technique through which the structure of a compound is observed; this process involves crystallizing the compound and exposing it to radiation to view the compound's shape; this was used by Franklin to reveal the structure of DNA